The term ‘circular economy’ can look vastly different across industries.
There are some great initiatives already in place in the mining industry to achieve mine site optimisation and integrate circular principles, however the shift towards a truly circular economy in mining is still an emerging concept.
WSP’s Circular Economy Lead in Australia, Valentina Petrone, said that it is important to remember that a circular economy approach is defined by three key principles:
- Design out waste
- Keep materials in use
- Regenerate natural systems
“What often happens across businesses and industries is that, unfortunately, we forget about principle number one (design out waste), which is very critical because whenever we design anything – and it can be the phone we use, the car we drive, a big mining site or infrastructure – the design is the part where we set the project in the right direction during the construction phase and across the whole life-cycle of an asset.”
Ms Petrone said that the second principle (keep materials in use) involves how an asset is maintained in good operation with planned maintenance. It also involves how to easily replace materials that require frequent replacement and what happens to the materials that reach the end of their useful life.
The third principle (regenerate natural systems) is often the most challenging in mining as it aims to support natural processes and build natural capital instead of continuously degrading nature through extraction.
Turning attention to mining
Ms Petrone said there is room for the implementation of circular economy principles in mining in several areas.
The first is applied to the initial design of the mine site itself. From the early stages of design – starting from the site investigation and master mine planning – it’s crucial to keep circular economy principles in mind. From a circular economy perspective it is just as important to maximise the lifespan and usage of the mining operation to extract the highest possible value, as it is to include the responsible retirement of assets during mine closure.
In terms of construction, there are some circular design strategies that can be applied. Thinking in terms of design for flexibility and adaptability is a valuable exercise to undertake, because an asset of certain capacity and volume that may currently be considered as necessary could experience a change in the future if additional reserves are identified.
During construction, there is an opportunity to address efficiencies, especially if constructing a new mine site or new infrastructure. The construction of mine sites can be done in a way to minimise wastage; buildings can be designed with water efficient fittings in mind, and they can integrate low carbon energy sources tied to the grid or as part of onsite hybrid power solutions.
Another place for circular economy implementation is the operations side, focusing on the recovery and reuse of byproducts and waste as much as possible. The most common application of this principle in mining involves reprocessing tailings materials to extract leftover minerals and construction materials. The responsible management of water resources is critical here too.
“At the end of the day, we want to try to keep materials in the loop as much as possible,” Ms Petrone said.
During the operational stage, mining companies should endeavour to progressively rehabilitate their footprint. This is not always possible and is dependent on the mining method, however, opportunities may exist to replace infrastructure which may present a reuse potential as part of its replacement.
At closure, plans for transitioning a mine to an agreed next use offer the largest opportunity to support natural systems, recreate new systems, or repurpose assets for alternative uses.
In keeping with the principles of a circular economy, mining clients need to go beyond ensuring they have the financial means to implement the conditions of environmental authorisations as part of closure planning and concurrent contaminated land rehabilitation planning.
Instead they need to limit or reduce adverse effects on the receiving environment.
Opportunities include incorporating long-term considerations and potential liabilities into operational designs to avoid and/or mitigate closure liabilities altogether, rather than simply planning to manage them in the future. For mining clients to retire their assets responsibly, closures must be thoroughly planned in advance and sufficient financial provision made for the retirement of assets.
“In terms of transition and regeneration, there is a bit of a planning issue at the moment in Australia. Where a mine site is allowed from a planning perspective, in 30 years we might not be able to build and reuse this site for a different purpose.”
This barrier is something that is sometimes discovered at the end of a project when it has not been planned in advance.
Ms Petrone said that considering the post-mining transition from the very beginning is a key step in adopting circular economy principles.
“We need to think about the whole life-cycle as early as possible, not just as an afterthought, because the risk is that we miss opportunities. It’s really about having a long-term mindset from the very beginning.
“It’s asking how we can design those assets thinking about the whole life cycle and what might happen in 50 years when the sites might come to a natural end, or if there’s another shift in the needs of the markets.”
When asked to pinpoint closed mine sites that successfully adopted circular economy principles, Ms Petrone referred to the Eden Project in the UK – where the land was used as much as possible before being converted into a place with different biospheres that are open to the public and a fully sustainable community hub and example of biodiversity.
Another example highlighted by Ms Petrone was the Municipal Stadium of Braga in Portugal – a stadium that was built in a former mine site with architects utilising man-made parts of the landscape.
A successful example closer to home is the Kidston Gold Mine, a former open cut gold mine in northern Queensland that has been reused as a pumped hydro storage system to support and store energy from a 50MW solar farm.
All three sites are, according to Ms Petrone, “good examples that not only resolve the problem of a man-made change in the landscape but also provide job opportunities for the local communities”.
This kind of mine reuse is a popular topic in Australia because there are examples in New South Wales and in Western Australia where cities or big towns were built around job opportunities that will be gone upon mine closure.
Although the examples are all different from each other, a common characteristic they share is thinking outside the box and viewing these mined environments as an opportunity instead of just a hole in the ground.
“I think the main lesson learned is the shift from seeing it as a problem to seeing it as an opportunity to build something new, as applicable.”
Although circular economy principles in mining are still relatively new, a focus on responsible mine closure is not, and there have been instances where adoption has not been successful, for a number of reasons.
“It’s a matter of barriers and I would say that regulation, planning and costs, including remediation costs, might be the main ones,” Ms Petrone said.
“There might even be local communities that are not happy about the different site uses. Contaminated soil could also be a big barrier. If we need to remove all those contaminants, it might come with a very high cost so an option might be just to do a remediation and not give people access to that site.”
For companies embarking on their circular economy journey it can be a daunting process and a good way to start the process is through some mapping.
“The first step is to undertake an audit of the mining company – understanding what assets exist, how they’re managed, at what stage they are within their life cycle – to map out what the next step will be. If they are open to designing new sites, having a very early assessment of what the opportunities are and what will happen in the long term.”
Ms Petrone said that another critical step is assessing the company’s opportunities from an industrial symbiosis perspective – seeing how the waste of one industry or one asset can become an input for another one, assessing one or multiple sites and seeing if there are any other surrounding companies or organisations that could benefit.
A perspective shift
A key element in increasing the adoption of circular economy principles in mining, according to Ms Petrone, is shifting industry thinking away from the idea that it requires extensive added effort and cost and towards viewing it as an opportunity instead.
“Circular economy is a novel approach in terms of how we are trying to manage waste differently to the point that, ideally, we won’t refer to it as waste anymore, but as resources.”
Ms Petrone stressed the importance to mining companies of carefully considering their options and doing some investigating to see how something that “might be an additional cost at the beginning, might even become cost neutral at the end of the process”.
Featured image: U2M Brand/shutterstock.com
